The use of reference calibration patches exposed on a roll of film to enable better exposure control during optical printing is known in the art. See for example U.S. Pat. No. 5,767,983 issued Jun. 16, 1998 to Terashita entitled Color Copying Apparatus for Determining Exposure Amount from Image Data of an Original Image and a Reference Image. The use of reference calibration patches has also been shown to be useful in determining correction values for scanned film data used in digital printing. See for example U.S. Pat. No. 5,667,944 issued Sept. 16, 1997 to Reem et al. entitled Digital Process Sensitivity Correction; and U.S. Pat. No. 5,649,260 issued Jul. 15, 1997 to Wheeler et al. entitled Automated Photofinishing Apparatus.
The film format known as the Advanced Photo System (APS) as designated in the System Specifications for the Advanced Photo System, referred to as the APS Redbook, reserves specific areas on an APS format film strip for use by photofinishing apparatus. These areas can be used for exposing reference calibration patches and other data used in the photofinishing process. Referring to FIG. 4, an APS format photographic element 10 with a geometry as specified in FIGS. 200-1, 200-2, 210-1, 400 and 600 of the APS Redbook is shown. The photographic element includes a first area 12 reserved for use in photofinishing apparatus, a first imaging frame 14.sub.1, a last imaging frame 14.sub.1, and a second area 16 reserved for use in photofinishing apparatus. Anticipation perforations 20.sub.1 -20.sub.n and metering perforations 22.sub.1 -22.sub.n are provided for each imaging frame on the photographic element 10. One additional end of roll perforation 23 is provided in a position corresponding to an anticipation perforation. For film strips intended for use in one-time use cameras, an additional end of roll perforation (not shown) is provided in a position corresponding to a metering perforation after the end of roll perforation 23.
The reserved areas 12 and 16 are wider (in the direction of the length of the photographic element 10) than exposed image areas (not shown) and printed or projected image areas (also not shown) that are located within frames 14.sub.1 -14.sub.n. Dimensions of these areas are noted in Table 1.
TABLE 1 Frame Width (mm) Height (mm) Reserved area 12 37.7 16.7 Reserved area 16 32.45 16.7 Exposed image area of Frames 14 30.2 16.7 Printed or projected image area of Frames 14 27.4 15.6
Some problems are encountered when utilizing reference calibration data applied to the reserved areas 12 and/or 16 on APS format photographic elements. One problem occurs when scanning the extra width in the reserved areas 12 and/or 16 using conventional scanning devices developed for scanning APS imaging frames 14. These devices are designed to scan images of size equal to or smaller than the exposed image area within the frames 14. Extra scanning hardware and software is required to scan the full width of the reserved areas 12 and 16. Also, additional memory may also be required to store the extra pixel information from the scanned reserved areas if the entire areas are scanned. Another problem occurs in locating the calibration data so that existing scanners can accurately and readily retrieve the data. A further problem exists with some existing scanners in that they are physically unable to access the second reserved area 16. A still further problem exists in that variations in placement of the calibration data during recording or the location of the photographic element during scanning can result in the failure to read portions of the data.
There is a need therefore for an improved method of recording calibration data on an APS format photographic element that avoids the problems noted above.